<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<h1>学了就忘</h1>
.ann {
border: 1px solid rgb(0,0,0);
width: 150px;
height: 100px;
font-size: 30px;
text-align: center;
line-height: 100px;
margin:  auto;
position: absolute;
top: 0;
right: 0;
bottom: 0;
left: 0;
background-color: #0eee06;
border-radius: 15px ;
box-shadow:10px 10px 1px rgba(15,15,15,.5),
inset 10px 10px 2px lightgreen ,
inset 12px 12px 2px lightgreen ,
inset 14px 14px 2px lightgreen
;
letter-spacing: 10px;
}
a:hover {
text-decoration: none;
color: red;
font-size: 50px;
}
a:link{
color: red;
text-decoration: none;
}
.ann:hover {

transform: scale(1.2,1.2);box-shadow: 0 0 10px #0000ff;cursor: pointer;

}
</body>
</html>